Depression is one of the most common psychiatric disorders among the elderly. Thiamine (Vitamin B1) has been hypothesised to play an important role in mental health. Inadequate Vitamin B1 intake and Vitamin B1 deficiencies may lead to physical and mental health issues. For example, thiamine diphosphate, the most bioactive form of Vitamin B1, is a coenzyme in glucose metabolism crucial for the secretion and metabolism of serotonin. It plays an important role in nerve conduction. In the elderly, Vitamin B1 deficiency is common and could induce mitochondrial dysfunction and chronic oxidative stress, which may contribute to depression. Oxidative stress due to Vitamin B1 deficiency may be linked to neuronal damage and decreased hippocampal volume in patients with major depression Additionally, a deficiency in Vitamin B1 may lead to irreversible neurological consequences such as Wernicke’s encephalopathy and peripheral neuropathy.
This study found a relatively high prevalence of subclinical Vitamin B1 in older Chinese adults. After adjustment for age, sex, city, and residence, lower concentrations of free thiamine, thiamine monophosphate, or thiamine diphosphate were associated with higher odds of being depressed (all P-trend < 0.01). The results of this study suggests an association between thiamine malnutrition and depressive symptoms among older Chinese adults.
Zhang G et al. Thiamine Nutritional Status and Depressive Symptoms Are Inversely Associated among Older Chinese Adults. J Nutr. 2013 Jan; 143(1): 53–58.